20.—(1) At no time while the ship is at sea shall any interference or mechanical noise produced by any radio installation required by this Part be such as to prevent the efficient operation of any other equipment installed on the ship.
(2) At no time while the ship is—
(a)at sea; or
(b)in port when a watch is required by the master equipment in the ship be sufficient to prevent the effective reception of radio signals by means of the radio installation.
(3) Any ship to which this Part applies in respect of which it is impracticable to erect efficient and properly installed antennas for broadcast receivers which do not interfere with the efficiency of the radio installation shall be provided with a communal antenna system for broadcast receivers.